Electric remote selector circuit



ocf- 1l, 1938- L. E. w. MONTROSE-OSTER 2,132,960

ELECTRIC REMOTE SELECTOR CIRCUIT Filed April 25, 1937 Patented Oct. 11, 1938 UNITED STATES 2,132,966 momo more salmon cmcurr Louis Eugne widou Mamme-om, carisma, Cxechoslovakia, asslgnor of cnllal! to Pollon Patents, Ltd., London, Ena'lnlulI Application Aprii 23, im, serial No. 13am In Germany may s, im

2Claims.

The invention relates to an electric remote selective control system with congruently sub- .divided potentiometers at the transmitter and at the receiver, the tappings of which are con- 5 nected to contact paths with a preferably resilient contact arrangement, anda compensating line arranged between the tappings which comprises a switching means for a controlling device of the driving motor at the receiver, and with devices for consuming the kinetic energy of the moving parts of the receiver, which become effective as soon as the parts Iof the re; ceiver have reached one of the positions predetermined on their contact path and respectively controlled by the transmitter, use being made of a plurality of diilerent'relays for controlling the driving motor of the receiver.

Such a circuit will hereinafter be referred to as of the kind described.

In similar remote selector circuits, it has-already been proposed to use motors of special construction. Part of the tapped exciting winding of such a motor is continuously traversedby the current, so that .the permanently existing field, on short-circuiting of the armature, almost instantaneously stops the'motor.

Furthermore, it has already been proposed to stop a motor ln a remote control system with polyphase current and polyphase potentiometers 30 and synchronous motors by shortcircuiting the armature, but with a eld constantly excited by the'mains supply.

Experience has shown that in the known arrangements, sunlcientl-y great accuracy of the adjustment cannot be achieved. 'Ihe control motor, for instance, often switches one step too far and begins to hunt on returning to the correct position.

'I'he invention allows the exact -observance of 4o the adjustments at the receiver in a system of the kind described, by'providiag a relay connection of a novel nature which stops the controllingwmotorv instantaneously assoon as the movable contact of the receiver 4has reached a point corresponding to the position of the movable contact of thetransmitter.

According to the invention, this is eiected by providing diierent timing oi' the electro-magnet l relays in such a manner that, on switching-oir the switching means in the compensating line,

6i) circuiting oi the armature.A

those relays Awhich switch the current to @the The accompanying drawing illustrates, as a constructional example, a diagram of this new circuit for the particular case of feeding with direct current. It is shown in detail in order to make the invention particularly clear.

Referring to the drawing, i and i' denote two identical potentiometers, one of which is installed at the transmitter A and the other at the receiver B. Each potentiometer is sub-divided into a number of steps a to i and a to i respectively, which are connected to a contact path 2 and 2 respectively arranged at A and B. Thezlever I can slide on the contact path at A and the lever l on the contact path at B. Through these levers, the voltage derived is transmitted to the inner rings 4 `and 4' respectively, The arrangement i to 4 therefore represents the transmitter and thev arrangement i' to 4' the receiver.

hand, at will to one of the contacts a to i of the path 2, the contact lever 3' of the contact path 2 is moved, for instance, through a worm wheel 5 and a worm 8 from an electric motor, the

amature and eld winding of which are de noted by 1 and I respectively.

A series-wound motor has been chosen for the example.

This motor is connected in series with a series resistance 9 to the mains supply. The'supply leads to the positive and negative pole are passed through dierent relays, which are successively Adenoted by I0, ii, I2, i3, i4 and l5.

In the compensating line I6 between the con' tact path 4 of the movable contact 3 of the transmitter and the contact path 4' of the movable contact 3' of the receiver, a polarized change-over relay il of well-known type is pro- A vided which makes contact by its movable conthereof flowing through the series resistance 22,v

theV coils of the relays l2 and |5,` the junction 23-and the lead 24 to the negative conductor, the other half flowing through the equally large sexies resistance 25, the coils of the relays I4,v

il, the junction 23 and the lead 2 4to the negative conductor. A The relay coils are given suchv dimensions that althoughv they may be per-y manently connected to' the mains voltage, the

While the lever 3 can be adjusted, e. g., by'

' closed-circuit current can only attract'the arma- A ture of the relay il, by which the armature 1' of the main currentmotor is short-circuited. In the case of the other five relays II, i2, il,

f the gear 5, 6 until this lever has reached the con- A taken place not only with a normally-excited.-

Il, I5, the closed-circuit current is unable to attract the armatures.

In the conditionV shown (condition of rest), therefore, only the relayl II has attracted its armature, whereby the amature 'I of the control motor is short-circuited. No current ows in the connecting line I6 between the members 0 and d', since they are connected through the contact levers 3 and 3' to the equipotential points g and y of the potentiometers I and I'.

,If the lever 3 is displaced, for instance, onto the contact c, a potential kgradient immediately arises from g to c, that is, at the terminals of the polarized relayVY I'I a. Ivoltage arises which causes this relay tomake contact e. g. at I8. Thereby, the coil of the relay AII and the series resistance 22 are short-circuited, so that the mains voltage now ows from the positive conductor through the supply lead 20, the coil \of the relay I0, the contact I8, the coils of the relays I2 and l5, the junction 23, and the lead 24 to the negative conductor. The current has now increased to such an extent that the relays I0, I2 and l5 attract their armatures. Therefore, at the moment when. the polarized relay has established contact at I8, the short-circuiting of the armature i of the control motor has been removed by the dropping-off of the armature of the shortcircuiting relay IIwhlle, on the other hand, the relays I0, I2 and I6 have switched-in the control motor itself. A current now ows from the positive conductor through the lead 20, the series resist nce 9, the amature of the relay I0, the armatur "I of the control motor, the armature of the relay I2, through the eld winding 8 in the direction from left to right, the armature of the relay l5, and the lead 24 tothe negative conductor.` e stance, in the direction of the arrow. In this case, it moves the lever 3'- downward through tact c' At this moment, the motor instantaneously stops. c ando' represent equipotential points, that is, the compensating current in the line It ceases to ow, the polarized relay I1 breaks the contact at I 8, and before the relays I0, I2 and I5 drop oi, the diierently timed relay .II has ali ready attracted its armature and short-circuited the armature 1 of the motor. Thereby, the motor instantaneously stops, since this short-circuit has iield, but evenwith an over-excited iield. By the short-circuiting of the armature 7, the resistance of the motor circuit has been reduced, which results in a. correspondingly greater current intensity in the motor circuit and, therefore, in the ileld winding 8. e

Experiments have shown that the control motor in this circuit stops 'deadin a fraction -of a revolution, even if its normal speed is above 1,000 revolutions. r

The lever 3 also follows the lever 3 in the same Way if the latter is displaced upwards. In this case, the 'current'in the connecting line I6 ows from 4 to 4', the polarized relay I'I responding before, tle bridge across the control motor arma- `ture 1. The relay I0 also attracts its armature. However, sincethe series resistance 25 is bridged-over this time, the-relays I4 and I3 respond, that is, the direction of the current in the eld winding 8 is, this time, from right to left, so` that the control motor runs in the opposite direction to its Apref'vi'ous direction, that is, against The motor starts running, for inf advisable. to choose contact the direction of the arrow, whereby the contact lever 3' is moved upwards..

It is thus possible from the station A to allow the switching lever 3 at the station B to assume at will a considerable number of diiierent positions, provided that a corresponding equal number of positions and, therefore, tappings of the, potentiometer is also provided at A. If the con-I trol relays are constructed in the manner indicated, not only an almost simultaneous movement of the levers 3 and 3' takes place, but it is also positively ensured that the lever 3' of the receiver will stop with almost mathematical accuracy at the predetermined position. The invaccuracy in the adjustment of the contact lever -remote control of rudderv motors for craft and of armoured turrets and the like.

Instead of the'selector lever 3, any other wellknown 'selector arrangement, for instance, with contact buttons or plugs, slide-rails, rollers, drums or the like, may be employed. It is only necessary that the lvoltage division at the transmitter corresponds to that -at the receiver.

The drawing illustrates, for better understanding, only the simplest construction of the potentlometers and contact paths. Of course, it is paths with resilient contact, movements.

What I is:

1. An electric remote and selective .control system, comprisingY a potentiometer at the controlling end of the circuit, a potentiometer of similar electrical characteristics at the controlled endv of the circuit, a compensating circuit connecting said potentiometers, a control motor having a iield winding, said motor controlling a circuit joining switch arms connected to said potentiometers, relay means for controlling the short circuiting of the armature of said' control motor, relay means controlled by said compensating circuit, for controlling the eld circuit and armature circuit of said control motor, said firstmentioned relay means being timed diiierently from said latter relay means, whereby the field circuit of vsaid control motor is maintained in energized condition while the armature is rst short circuited and thereafter the eld circuit and armature circuit are opened by said secondmentioned relay means to effect a quick stoppage of the control motor responsive to the movement of the switch arm of the potentiometer at the controlling end of the system.

2. An electric remote and selective control system according to claim l, in which the kinetic energy of the moving parts of the control motor is utilized by the short circuiting of the armature of said control motor, which occurs before the opening of the circuit of the eld of said control motor, under simultaneous strengthening ofthe eldfof said control motor.

Louis EUGNE WIDoL'r MONTROSE-cerne. 

